Compact Radio Cores in Seyfert Galaxies

Abstract

We have observed a sample of 157 Seyfert galaxies with a 275 km baseline radio interferometer to search for compact, high brightness temperature radio emission from the active nucleus. We obtain the surprising result that compact radio cores are much more common in Seyfert 2 than in Seyfert 1 galaxies, which at first seems to be inconsistent with orientation unification schemes. We propose a model, involving optical depth effects in the narrow-line region, which can reconcile our result with the standard unified scheme. (Accepted for publication in ApJ 1994 Sep 10)

21 pages and 7 figures, uuencoded tar-compressed postscript files, ATP189

Cited by in corpus (33)

• Chandra Snapshot Observations of Low-Luminosity AGNs with a Compact Radio Source
• Radio Continuum Survey of an Optically-Selected Sample of Nearby Seyfert Galaxies
• Completion of a Survey and Detailed Study of Double-Peaked Emission Lines in Radio-Loud AGNs
• A Survey of Kiloparsec-Scale Radio Outflows in Radio-Quiet Active Galactic Nuclei
• Hidden Broad Line Seyfert 2 Galaxies in the CfA and 12micron Samples
• The Unified Model & Evolution of Active Galaxies: Implications from a Spectropolarimetric Study
• High-resolution radio observations of Seyfert galaxies in the extended 12-micron sample - I. The observations
• The spectral energy distribution of the central parsecs of the nearest AGN
• VLBI Imaging of Luminous Infrared Galaxies: AGN Cores in Mrk231, UGC 5101 & NGC 7469
• Statistical Properties of Radio Emission from the Palomar Seyfert Galaxies
• A Radio Study of the Seyfert galaxy Markarian 6: Implications for Seyfert life-cycles
• The Radio Properties of Seyfert Galaxies in the 12--Micron and CfA Samples
• Parsec-Scale Images of Flat-Spectrum Radio Sources in Seyfert Galaxies
• The Unified Model of Active Galactic Nuclei: I. Non-hidden Broad Line Region Seyfert 2 and Narrow Line Seyfert 1 Galaxies
• High-resolution radio observations of Seyfert galaxies in the extended 12-micron sample - II. The properties of compact radio components
• Dressing a naked quasar: star formation and AGN feedback in HE0450-2958
• Parsec-scale radio structures in the nuclei of four Seyfert galaxies
• Is there really a dichotomy in AGN jet power?
• Milliarcsec-scale radio structure of a matched sample of Seyfert 1 and Seyfert 2 galaxies
• Evidence for a black hole in a radio-quiet quasar nucleus
• Outflows in the inner kiloparsec of NGC 1566 as revealed by molecular (ALMA) and ionized gas (Gemini-GMOS/IFU) kinematics
• First Results from the COLA Project- the Radio-FIR Correlation and Compact Radio Cores in Southern COLA Galaxies
• Detection of a Parsec-Scale Jet in a Radio-Quiet Narrow-Line Seyfert 1 Galaxy with Highly Accreting Supermassive Black Hole
• Seyfert galaxies: Nuclear Radio Structure and Unification
• Radio Emission from AGN detected by the VLA FIRST Survey
• The filamentary radio lobes of the Seyfert-Starburst composite galaxy NGC3079
• A New Radio Loudness Diagnostic for Active Galaxies: a Radio-To-Mid-Infrared Parameter
• Looking for Signatures of AGN Feedback in Radio-Quiet AGN
• Hard X-ray Luminosities of Multinuclei Infrared Luminous Galaxies Showing a Radio/Far-Infrared Excess
• Detection of the H92alpha recombination line from the starbursts in the Circinus galaxy and NGC 1808
• A parsec-scale faint jet in the nearby changing-look Seyfert galaxy Mrk 590
• Multicolour Optical Imaging of IR-Warm Seyfert Galaxies. V. Morphologies and Interactions. Challenging the Orientation Model
• Embedded AGN and star formation in the central 80 pc of IC 3639